1. Field of the Invention
The present invention relates to an automatic transmission, and more particularly, to a stepless automatic variable transmission assembled in such a way that power input to an input shaft can be converted and transmitted to an output shaft without changing or disengaging gears when accelerating or changing speed to initiate and maintain forward motion and when reversing the rotational direction of the output shaft to initiate and maintain a backward motion.
2. Information Disclosure Statement
In the conventional manual transmission, speed changes are accomplished by constantly choosing among different given gear ratios in accordance with the load. Such constant attention is annoying in that the gears must always be disengaged and/or engaged at the time of a desired or necessary speed change. Also, the existing automatic transmissions and belt type stepless automatic transmissions are complicated in design and structure and require a large dedicated installation area. Furthermore, such transmissions are expensive to manufacture.
The above problems are addressed in U.S. Pat. No. 5,062,823 which issued on Nov. 5, 1991. However the transmission described therein requires a separate means for reverse rotation of the output shaft thereby severely restricting the versatility of the transmission.
Other transmissions which have solved the problem of initiating and maintaining a backward or reverse motion include: U.S. patent application Ser. No. 07/903,137, (filed Jun. 23, 1992), now U.S. Pat. No. 5,326,334, Ser. No. 07/920,892 (filed Jul. 28, 1992), now U.S. Pat. No. 5,322,488, Ser. No. 07/921,050 (filed Jul. 28,1992), now U.S. Pat. No. 5,330,395 and Ser. No. 08/028,824 (filed Mar. 10, 1993) now U.S. Pat. No. 5,364,320.
However, the present invention uses a design and construction of a speed change system which is different from the above described systems and includes an overdrive function which increases the rotational speed of the output shaft over the rotational speed input by the engine, or the like. A speed change controlling system in which the speed can be adjusted steplessly and automatically is also utilized in the present invention.
Therefore, the objects of the present invention are to provide a stepless automatic variable transmission which can solve the above described problems which have yet to be efficiently and effectively solved in the prior art.
Another object of the present invention is to provide a transmission which is not as complicated as those of the prior art, includes a very reliable speed change operation, has smooth rotational output, quickly adapts to a change in the load and which includes overdrive and reverse operations.
Another object of the present invention is to provide a continuous variable automatic transmission which efficiently transmits rotational output in either rotational direction and which is simple to construct and easy to maintain.
The preceding objects should be construed as merely presenting the more pertinent features and applications of the invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to both the summary of the invention and the detailed description, below, which describe the preferred embodiment in addition to the scope of the invention defined by the claims considered in conjunction with the accompanying drawings.